1. Technical Field
The present disclosure relates to backlight modules, and more particularly to a light emitting diode (LED) backlight module having a lens.
2. Description of Related Art
A conventional LED backlight module includes a backlight plate, a plurality of LEDs mounted on the backlight plate and a lens covering the LEDs and mounted on the backlight plate. The lens is manufactured by injection molding. A mold for the lens is machined by high precision tools and a plurality of concentric recesses is defined in an inner surface of the mold. When the lens is manufactured, a plurality of glue is filled in the mold and solidified by heat. A plurality of concentric protrusions is formed on an outer surface of the lens according with the concentric recesses in the mold. When light emitted from the LED radiates through the concentric protrusions of the lens, a plurality of concentric halos is obtained. Thus, the light of the conventional LED backlight module is unevenly distributed.
What is needed, therefore, is an improved LED backlight module which overcomes the above described shortcomings.